sharp subjects?

Hi all.,...I am (in case you hadn't already guessed) a big lover of portraiture and am getting rather happy with my 'one subject' portraits.... after advice i tend to activate only one sensor, and use focus lock, to get a good sharp shot of the subject...... now, my dilemma is shooting portraits of 2 or more people... i should then activate all sensors to get everyone sharp???? Have been finding one person to be sharper than others which i am hating with a passion!!!!!!!....Should i be shooting on a particular mode or using specific settings to combat this problem??... i tend to swap around from Av to Program.... I would love to know what you professionals use any advice on getting all of my subjects SHARP is greatly appreciated! I understand that lighting plays a massive part but is there a general rule-of-thumb for shooting multiples??? xx Thanks in advance and sorry if this is a laughable question - I am so far self-taught only apart from a short course basically on 'getting to know my camera' but hoping to book into a course in the near future. thanks again xx

Here is an example...

Here Chloe looks sharper than JAy??!!... I use a canon 350D with 18 - 55mm lens shot on aperture priority... If i used a 50mm 1.8lens, would this help to make it sharper too?? x

Experiment in the Av mode with apertures ranging from f8 &#8211;f16. You want to keep the background out of focus but give yourself at least some room to play with DOF. In a lowlight situation like this it would be hard to hit f8 without using flash or going to a much higher ISO.

Thanks Brittany & AIRIC... i was thinking along those lines.... i love the effect of a wide open aperture blurring the background making subjects pop, so without checking i'd say the aperture was 3.5ish? I have heard this rule about getting faces as close together as you can, trying to align eyes too, so they are both on the same 'plane'.... but what to do when i want them not so close together... will dropping the aperture fix this problem?... thanks xx

Yes, using a smaller aperture will help this problem. It will give you a deeper DOF which should help keep both subjects in focus. Also, does your camera have a DOF preview button?

Your DOF is the range of distances that will appear in focus. If you focus on a spot, your DOF will be 1/3 in front of the spot and 2/3 behind the spot. So if you have two subjects, you would be better off to focus on the closest subject and use a small enough aperture to get the farther subject into focus.

I know I was pooh poohed in the other thread, but just give it a try, ok? Use your center focus point, select the right ISO, and open the ap up as wide as the lens will go. Aim your focus point dead between the eyes on the kiddo on the right (doesn't matter which kid really), and then recompose to the bridge of the nose on the second kid and fire away. You will have a nice blurred background, but two kids whose eyes are in super sharp focus, and faces that are well in focus.

Aim your focus point dead between the eyes on the kiddo on the right (doesn't matter which kid really).

Click to expand...

This is exactly what I'd do.

Just remember... if one of the subjects it slightly closer to the camera, focus on THAT person. The vast majority of DoF is BEHIND the plane of focus. In other words, don't expect anything closer to the camera to come into accecptable focus.

thank you thank you thank you thank you! Listening to you guys really makes all the stuff i am reading make more sense!! Bought my 50mm1.8lens yesterday and am ready to test her out today - my poor kiddliwinks!! - hope to post something for you later today! thanks again x